Ceramic article and material and method for coloring or shading the same



Aug. 20, 1946. R. w. ERDLE 2,406,208

CERAMIC ARTICLE AND MATERIAL AND METHOD V FOR COLORING OR SHADING THE SAME Filed March 4, 1944 f f @a INVENTOR. v /eL'IZer WE/dl Patented Aug. 20, 1946 CERAMIC 'ARTICLE AND MATERIAL METHOD FOR COLORING VOR SHADING THE SAME j `,Reiner W.v Erdle, Chicago, Ill., assignor to Dental Research Corporation, Chicago, Ill., a corporation of Illinois Application March 4, 1944, seriai No. 525,012

This invention relates, in'general, to ceramic articles and Amaterial and meth'od for producing the same, and has particular relation to an improved material and method for producing different shades or colorsalong different portions of suchY articles and to the articles .thus produced.

While the invention is particularly adapted for producing lfrom a singleporcelain mixvcommercial Aru'ns of artificial teeth having uniformly throughout therun `of teeth' different shades along different portions of such teeth accurately to rmatch a standard ,shade guide or the natural teeth, it is tobe understood that the invention, in its broader aspects, is not limited v4to this particular use butfmay beemployedin all similar Work-for example, ,.for-- producing different shades or colors along different portions of other ceramic articles.

Heretofore, in order to produce diiferentsh'ades in different parts of an articial tooth, porcelainsy of differentv colors were manufactured. These porcelain powders of diiferent colors were mixed with distilled water, or other suitable binders, into separate porcelain mixes, one for each color. The lighter color porcelain mix and a definite amount of it was placed ,in the tooth cavity of the mold. Through gravity or vibration, for example, in the Imanner set forthV and claimed in my prior U. S. Patent No. 2,196,258, issued April 9, 1940, this porcelain mix would ow to the lower part of the mold cavity and form'the incisal part of the tooth. 'Ihe second color mix ofv porcelain, having the color ofl the middle section of the tooth, was then introduced into the mold cavity, and finally a third color porcelain mix, having the color of the gingival part of the tooth, was introduced into the mold cavity.

It was not always necessary to use three different colored porcelain mixes `to produce a tooth having the deiinite shades along different parts thereof. It was found that by carefully mixing the colored porcelain powders, two difierent colored porcelain mixes could be used to produce a porcelain tooth oi"y a given shade.

` In order to produce a given shade in a porcelain 9 claims. (c1. szf-s) tooth with two or more different colored porcelains, th'e operator must exercise extreme care to put the proper amount ofthe different colored porcelain mixes intothe tooth mold. l The time element is also ofgreat importance. If 1to0 much time elapsesbetween the filling operations of the different porcelain colors, a sharp line will ap-` pear on the tooth, caused by the different colored porcelain mixes.v If there is insuflicient time be' tween the filling operations, th'e porcelain Icolors will runtogether in the tooth mold, and the porcelain tooth so produced will have substantially one color. This, of course, is undesirable.

In handling two or more porcelain mixes which havedifferent colors, considerable time is consumed,and the results .depend uponlthe skill of, the operator.- Teeth are produced in` this mailner in different dental laboratories throughout the country and in other countries. They .have to match a standardor given shade guide, and.y because the resulting shading of aV tooth depends to a large extent on the skill ofthe operator it has been difficult to obtain reasonably accurate matches of manufactured teeth with a standard or given shade guide.

One of the main objects of the present invention is to overcome the difculties above set forth and other difficulties-previously encountered in the production of porcelainteeth.

for automatically shading a tooth correctly, thereby raising the standard of the teeth.

'Another object of the invention is to provide for producing a tooth with its parts of different shades from a singleporcelain mix, thereby reducing the labor cost and eliminating any error an operator may make in handling two or more different colored porcelain mixes toiill the toothmold cavity.

Another object of the invention is'to provide an improved tooth porcelain and an improved tooth porcelain mix; also an improved method for assuring a better shading'of thev porcelain teeth and that the different shades in diiierent parts of each tooth of a commercial run of teeth ical section of a porcelain powder embodying ther present invention; l

Figure 2 shows, more or less diagrammatically, a mold having a tooth cavity filled With thesingle lporcelain mix of lthe present invention; and

Figure 3 is an enlarged perspective View of a tooth formed according to the present invention.

Referring, in general, to the more or less 'diagrammatic illustrations-inthe drawing, I provide, according tothe `present invention, a new and improved porcelain which may be referred to as Another object of the invention is to provide Y1 a single mix porcelain,jto distinguish from the part of the tooth.

plural mix porcelains previouslyV employed.

. As shown diagrammatically in Figure 1, this i new and' improved porcelain has relatively coarse f porcelain particles I made of a lighter shade porcelain having, for example, the color of the incisalpart of the tooth. It also has finer porcelain particles I I, and still finer porcelain particles I2. The particles II, which are of a grain size,

nextsmaller than thegrain size of the particles bl), are made of a darker shade, having thecolor of the middle part of the tooth. f The particlesIZ;

of next smaller grain size, are made of a still darker shade, having the color,v of', the ginrgival The porcelain particles lain tooth; The single: porcelain, mix is produced byV thoroughly mixing this mixturev of'por` celain particles I; II, and I2 With a definite amount of distilled water,or other suitable binder, to produce asingle Vporcelain. mix of the desired. consistency` and having all ofthe required colorsor shades in thesingleporcelain mix.V

The tooth cavity I3* of the vmold isthenfilled Y VvvithLtl'iissingle porcelain'mix, as shown at |75,

thus introducing allo'f the representative lots of porcelain particles'fI, II, and I2 into the cavity; I3 completely tolll the'same in a Single operationA and without successively introducing porcelainmixes of different colors into different parts of the mold cavity, as heretofore required. VThe porcelain mix I5 is introduced'into the mold cavityfI'While all of the various porcelain particles Il), II, and'IZ, of dif(-` ferent colors or shadesanddifferent grain sizes,A y and in predetermined amountsfare vmixed-vtof gether to produce a single porcelain powder hav-` ing all of the colors or shades required in a porcethe tooth. The finer porcelain particles will ll Y in the spaces between the Acoarser particles to produce an accurate and uniform overall blend- `ing of colors so that the resulting tooth Willfol- Y low the shade of natural teeth.

i After `the.tooth, as shown at I1 in Figure 3,

. .Y is removed from the mold I4, it may be dried and iirehardened--and glazed as more fully disclosed infrny4k previously` mentioned U. S. Patent No.

22,196,258.A Y,'Iheporcelain tooth I1 selected for illustrationgisfananterior tooth, but, of course,

this may vary. The incisal Vpart I9 of the tooth vI-'I Vis formedf by the -coarserV grain particles III apparent that the use'of the single mix porceV lain has the advantage ofrautomatically'shadf having, the color of the incisal shade of the tooth.-y The middle rpart 2D of .the tooth isformed by the next i'lner particles VIIhaving thecolor, of Vthe middle partof the tooth.r The'gingivalfpartV 2| is formed bythe next finer particles I2 hav ing'the color of the gingivalipart of thertoothl.

' From the foregoing description it will now be ing la toothcorrectly, thereby raisingr the stand- IIJ, II, andv I2 are in complete suspension in the binder. This assures the desired' shading of the tooth, and also assures that the different shades indifferentjparts of eachtooth of a commercial run ofteeth will accurately and uniformly match, for example, `a standard or givenshadeguide.

All of the porcelainparticles III', II', andY I2 of different colors and different grain sizes may f,

be kept in complete suspension during introduce` tionv ofv the single porcelain mix intov the mold cavity I3 i and up to that time, for'example, byV the.Y method and means disclosed. and claimed in my copending application Serial No. 522,706', filed February' 17,' 1944,

The moldV Ill'may bea flexible mold of the characterdescribed and claimed inv my prior U. S.

PatentNo. 2,337,636', issued December 21, 1943',

although, of course, this may varyyvvith-in the scopev of the present invention.

Upon fillingthe mold'cavity-I3 with thefsingle porcelain mix, the mold I4 and porcelain mix I5 in the cavity I3 thereof" are vibrated, for example,y as morel fully' described and claimed in my prior'U. S., Patent No. 2,196,258, issued April 9, 1940; Vibrating means for this purpose is shown more ori-ess diagrammatically at I6.' The particular manner in which thedesiredvibration `is-secured, and the particular form of the vibrating means may, of course, vary widely.

A The diierent size porcelain particles II), I I, and I2 have different'settling characteristics. The particles Ill, vWhichare coarser or of larger grain size, .will settle atonce to the bottom of the mold cavityA I3. The next nner particles Il settle over the coarser particles I, and where particles I2 of'aY third grain size are employed, as described, thesestill ner particles I2 settle over the particles I I of intermediate grain size. In this man.`

ard of teeth producedv according to thel present invention. The lillinggofthe tooth moldcavity IS'ninvolves thevvhandlingV of onlyV one porcelain mix,I which reduces considerably the labor,` cost for `producing, porcelainL teethkgThe use*V of the singlemix porcelain elimn'ates'also anyY error anfoperator may makeby handling two or more l different coloredY porcelains to1 filla tooth mold cavity. As a result, I 'secure' better shading-1er' coloring of the tooth, and I assure uniform and accurate lmatching of all teeth of a given commercial runof teeth Witha lstandard or given shadey guide.

If. desired, some of the; porcelain particles Il) may. beuncolored and other of Asuch particles II),V may be colored toshade theincisal part of the tooth by ablending ofthe colored and uncolored porcelain. Likewise, some of the porcelain particles IIV and/0r some of the particles l2 may be uncolored and .other of such particle'smay be colored toshade thetoothY alongl its middle and gingivalparts by ablending of these colored and Y uncolored porcelain particles.

One suitable porcelain for purposesV of the present inventionis composed of. minerals and mainly of nepheline. syenite, as more fully de -v scribed in. my prior U.V S. PatentNo. 2,334,319, issued November 16, 1943.Y This particular. mate,- rial is referred to for purposes'ofiillu'stration, it being understood' that'other ceramic materials and like materialsmay .bev employedr within the scope ofthe broaderaspects ofthe present,ini

vention. d y l VI have describedthej invention in connection With the details vof a particular embodiment, but Ido not rintend thereby` to limit the. inven'tiontol such details, nornd'o I intend'to be'limited tothel particular embodiment and relation". ofifthezessential features shown and described."l

1. VA unitary dental porcelain mix comprising a liquid binder `and differentially ground particles of vporcelaininitially, andprior togrinding; off different colors and in which the differentially ground porcelain particles initially ofdilerent' colors' are combined in proportionsadaptedto produce by thev differentsettling., characteristics 5 of the different size particles a predetermined shaded coloring effect in an article formed of snchmix.

2. An improved dental porcelain mix ccmprising a liquid binder having mixed therewith relatively coarse porcelain particles colored to produce the desired color along the incisal portion of a tooth, liner particles of the same porcelain material but of a different color to produce a different color along the middle third of the tooth, and still nner particles of the same porcelain material but of a still different color to produce a further color along the gingival portion of the tooth.

3. As a new article of manufacture, a ceramic tively coarse porcelain particles shaded to produce the desired shade along said portion and another portion formed of nner porcelain particles of a different shade to produce a different shade along said other portion of the tooth.

5. As a new article of manufacture, a porcelain tooth having an incisal portion formed of relatively coarse porcelain particles shaded to produce the desired shade along the` incisal portion and a gingival portion formed of nner porcelain particles colored or shaded to produce a different shade along the gingival portion of the tooth.

6. As a new article of manufacture, a porcelain 'tooth having an incisal duce the desired shade along the incisal portion,

a middle third portion formed of nner porcelain particles shaded to produce a different shade along said portion, and a gingival portion formed of a still finer porcelain particles shaded to produce a still differentshade along the gingival portion of the tooth.

7. As a new article of manufacture, a ceramic article having a shaded coloring effect with relatively coarsely ground ceramic particles initially, and prior to grinding, of one color forming one of the colored portions of the article, and relatively iinely ground particles initially, and prior to grinding, of a different color forming another portion of the article. Y

8. As a new article of manufacture, a porcelain tooth having an incisal portion formed of relatively coarsely ground porcelain particles initially, and prior to grinding, of a relatively lighter color to produce the desired color along the incisal portion of the tooth, and a gingival portion formed of relatively finer ground porcelain particles initially, and prior to grinding, of a relatively darker color to produce a different color along .the gingival por-tion c-f the tooth.

9. A unitary ground porcelain material comprising differentially ground particles of porcelain initially, and prior to grinding, of dineren-t colors and in which the differentially ground porcelain particles initially of different colors are comloined4 in proportions adapted to produce by the different settling characteristics of the different siZe particles a predetermined shaded coloring effect in an article formed of the material.

REDIER W. ERDLE. 

